Aircraft structure



j'. V. MARTIN.

AIRCRAFT STRUCTURE.

A APPLICATION FILED Nov. 14. 191s.

Patented May 30, 1922.

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l. V. MARTIN.

AIRCRAFT STRUCTURE.

APPucATioN man N ov. 1.4. 191s.

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.wf m ,//Mw KQ J.`V. MARTIN.

AIRCRAFT STRUCTURE.

APPLICATION FILED Nov. I4. I9I8.

1418008D Patented May 30, 1922.

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I. v. MARTIN.

AIRCRAFT STRUCTURE.

. APPLICATION FILED NovI I4. Isls.

Patented May 30, 1922L 9 SHEETS-SHEET 4.

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C) noz nu |10 J.V.MART1N. "MRCRAFT STRUCTURE.

APPLICATION FILED NOVn 14.

ma" Patented May 30,1922.

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J. V. MARTIN.`

AIRCRAFT STRUCTURE.

APPLTCATTON FTLED Nov` 14, T918. l ,418,908. Patented May 30, 192i 9 SHEETS-SHEET l.

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I.' v. MARTIN.

AIRCRAFT STRUCTURE.

APPLICATION FILED NOVa 14, 1918.

Patented May 30, 1922.

1. V. MARTIN.

AIRCRAFT STRUCTURE.

APPLICATION FILED NOVI. I4, 1918.

AIRCRAFT STRUCTURE.

Lemans.

citizen ofrthe United States o f America, rew siding at Elyria, in the county of Lorain,

State of Ohio, have invented certain newV and useful improvements in Aircraft Structures, ofwhich the following is a specifica i tion, reference being had therein to the accompanying drawings.`

This invention relates to certaln new and planes and one of the objects thereofV is to provide a construction'of chassis and fuselage whereby the chassis frame may be yhoused partially in the fuselage and partly in the wing structures, thereby permitting the `use of'a narrow fuselage and a chassis having a wide tread. A further object is to provide means for raising or lowering the chassis, which means isI constructed to hold the chassis in any position to which it is adjusted, thereby permitting the chassis to function as an alighting device in any projected position, and,L also toA provide means for automatically projecting or re.-

tracting the chassis, sald means being ar ranged to employ, broadly, the action of air currents set up by the aeroplane in iight, as a motive power for operating the "Y chassis. A further object is to reduce head lresistance to the minimum by streamline wheel housings and other parts, and providing a flush closure for the chassis housing\ together with means for automatically peratlng said closureto open or close the same. 1t 'is also an object of the invention to provide a very slight, strong and rigid fuselage framing and bracing construction, and to provide certain other nexv and useful featuresv in the construction, arrangement and combination Gfparts, -all as hereinafter more fully described. I lifith'these and other ends in view, the invent/ion consists in the" matters hereinafter set forth and more particularly' pointed out .in the appended claims, reference being had to the accompanying drawings infwhich- Fig. 1 is a plan view of an aeroplane embodying features of the invention;

Fig. 2,- a front end elevation of the same; Fig. 3, a side elevationyof the same; Fig. 4, :is a detailview showin lelevation of the 'fuselage or body F ig. 5, a plan view of the sam'e;

a side raming useful features in the construction of aerospecification of Letters Patent. Patented May 30, 1922.

Application' filed November 14, 1918. Serial No. 262,477.

,la F ig 6, an enlargediransverse section of the same; c

Figs. 7 and 8 are Sectional details of the framing;

Fig. 9 isa perspective detail of a portion of the framing; Y

v Fig. 10 is a sectional detail showing the forward part of the fuselage with a foldable chassis attached andA mechanism for operating the chassis;

IF ig. 11 is a transverse section through Fig. 10, showing the chassis and its operatin mechanism in elevation; ig. 12 is a sectional detail of ,power transmitting meansY for raising and lowering the chassis; f lj Fig. 13 is a sectional detail of a worm drive forming a part of the power transmitting means; 1

Figs. 14 and 15 are side and end elevationsyrespectively of a pivot bracket for attaching the chassis to the fuselage; Y

Fig; 16 ils a detail view of means for controlling the' power transmitting means;

Fig. 17 is a diagrammatic view illustrat ing a flexible skin covering for a' joint between a rudder or other vplane and the part to which it is pivotally attached;

Fig. 18 is a sectional detail of a rack and guide yoke with a shaft and its` pinion in elevation;

F ig. 19 is asimilar view with the yoke in elevationand shaft and pinion removed;

ig. 20 is a sectional view substantially upon the line of Fig. 18

Fig. 21 is a face view of a portion of the rack;

Fig. 22 is an inverted plan View of a portion of the fuselage and lower wings, showmodiication in the means for raising or re iEfs PATENT carreau tracting the chassis and alsoshowing the closure' for the opening in the fuselage and mechanism for operating the closure;

Fig. 25 isa front end elevation of F ig. 24, drawn to a reduced scale; and

Fig. 26 is a perspective view of controlling .x

means for releasing holding dogs for chassis elevating racks and for controlling the automatic opening and closing of the closure.

In Figs. l, 2 andy of the drawings a particular type of aeroplane is slio'wn but it, will be understood that the several inventions may be embodied in other types of aeroplanes, the one shown being merely illustrative of the application of new and useful features to an aeroplane construction.

In Figs. 1, 2 and 3 A indicate the fuselage or body, B the upper main sust ining plane or wing, and C the lower wings.

The plane B is provided at its ends with the usual ailerons D and atthe forward end of the fuselage is the propeller E driven by a suitable motor F located at the ,forward 'end of. the fuselage and mainly inclosed u therein. At the rear end of the fuselage is the usual rudder G, and stability planes H having the usual rearwardly extending altitude planes I.

-F igs. 4 to 9 inclusive illustratethe construction of the fuselage framingwhich consists of four longrons 1 spaced by suitable vertical struts 2 and horizontal top and bot" tom connecting bars 3, together forming in cross section a rectangular structure which` is tied together transversely by diagonal, brace rods '4. l i A Diagonal tension and compression m'embers 5 areJ interposed between the end of the struts 2, extending diagonally across the space between adjacent struts/and at the forward end of the frame, to provide Ia strongI and rigid engine support, m'embers'G of a4 construction similar to" the members 5 are secured at their upper ends in spaced relation along the upper longrons and#` converge downwardly to a substantially common connection with the lower longrons.

^ To provide a very light, strong and rigid fuselage framing, the longrons 1 are reinforced between the struts 2 by a plurality ofsheets of veneering glued together and laid upon` theJ outer facesof the longrons,

these 'built-up,l reinforcing strips 7 being curved at their free edges to provide great-' est .width intermediate their ends between the struts,` these reinforcements thus lending maximum strength to the longrons with a minimum addition of weight. .The several struts 2 and cross members are made up ofv an'outerfacing 8 comprising layers of veneer glued togethero and formed4 with edges which are curved to give greatest .width to the facing intermediate its ends, the facing being narrowed toward the juncture 4of the mem# oer with its longronsl Securedto the inner side of the facing 8 and extending inwardly of the frame work at right angles to the facing, isI acenter member or rib 9 formed of plies of veneeringand this strip isfalso curved at its free edge toward it-s .ends to provide its greatest width midway between the longrons.V The angles d between the facing and strip or web 9 are partly filled by corner-strips 10 and vthus these members are T-shapedin cross section with their ianges formed of veneering and the meeting angles filled in bycorner stripsI to more securely unite the web 9 to theouter strip or facing 8. These struts and bars thus have 'great strength, becauseof this particular construction to withstand very. heavy tension and compression strains and stresses with the least possible weight of material.

`To securely unite and brace, these struts and bars at their points of meeting lwith the longrons, angle webs 11 are provided by 80- continuing one or more of the layers of veneering of the inner web 9 into and. between layers of the corresponding web inthe adjacent strut`or bar,as shown in Fig. r9, thus firmly uniting a strut and bar by a web of veneering extending across their meeting angle which web is-properly curved to give the desired appearance and taker up less space within the frame. j

The ends of the bars and struts where they meet the longrons may be secured thereto in any suitable manner and thisfjointtis reinforced bymeaxns of angle plates 12 of veneer or othersu'ltable material and suitably formed to extend across the meeting angles ofthe struts and bars with the longrons. TheseV plates are glued or otherwise secured to the o iter faces ofctlie framing members, and thug the struts and bars are securely attached to the longrons and the meeting angles reinforced and braced to give the maximum strength with ay minimum of weight to the entire framing structure.

Secured to the forward end bf the fuselage near the forward ends of thelower longrons and adjacent the point of convergence of the struts 6, are .two journal brackets 13 shown in detail in Figs. 14 and 1.5, for the pivotalattachment of the chassis frame 14 to the fuselage. This frame comprises an upper transverse member having projecting ends or studs to engage the bearings of the brackets 13 which brackets are -each formed with an enlarged bore 13a'to provide-enlarged bearing surfaces forthestuds of the frame; thus giving avery strong and rigid pivotal attachment of the\ frame to the fuselage. As these brackets lare attached to the fuselage substantially at the point of convergence of the struts 6, theshockand strain of alighting comes `upon the fuselage atv its strongest point and where the greatest weight is car- The pivotalA attachment vof `the chassis frame 14 to the fuselage ,permits of its retraction or upward folding in flight, but as the .chassis axle mustjbe of greater lengthv thanlthe width of the fuselage in order to l provide the nehessary width of j'tread to properly support 'the extended wing vspread in alighting and to obviate making the fuselage' so yvide as to be impractical, the lower.v

wings are constructed to permit "such folding of' the chassis, the Wing spars indicated.

' in'dottedflines at C and C2 in Figs. 3,

` to receive theglegs 10, 11 and 22,'being so positioned and spaced as to permit the wheels of the chassis to be brought or swung upwardly between them, said spars being firmly secured at their inner ends to the fuselage and continued outwardly along the wings directly beneathA f the lower ends ofthe Kbars which are at-v tachedtheretof'thus providing a very rigid wing structure, the strengthaof which 'is unimpaired by the .housing of the chassis therein in the manner hereinafter described. The b\ott0m sln'n of the fuselage is formed 'with' grooves or recesses 17 (Figs. 22, 23 and 24) j Y A18 and diagonal brace members 19,0f the frame ll'when the frame is swung upon its pivot .rearwardly and upwardly'towardth'e lower side of the fuselage, these frame members bein .preferably stream lined `and the grooves 1 formed of such cross sectional dimensions as to contain the /frame members, which, w/,henxposi-- tioned therein, close these slots .or grooves by reason of the front face of the members lying substantially flush with the outer surface of the fuselage skin. The axle 16 is of greater length than the width of the frame 14 so that its end portions upon which the wheels 15 are mounted extend beyond the vertical plane of the sides of the fuselage, thus giving the landingvchassis a comparatively wide base and permitting of a comparatively narrow fuselage. The projecting ends ofthe axle `are strengthened by continuing the diagonal-brace`members 19 be-y yond the sides of the frame to a point of meeting with the axle adjacent to the wheels f and these wheels are partially housed when the chassis'is in folded position byproviding a housing 20 therefor upon each lower Wing C, which housing is preferably stream lined to reduce head resistance. The wheels are thus moved by the folding of the chassis,

from a point lforwardly of the `center o f gravity of the aeroplane, rearwardly to po sition within ythe housings.. The portion 21 of each wing between the housing 20 andl the fuselage, is formed to enclose the bearing brackets 13 and is also formed with -asuitable recess to receive the projecting end portions of the axle 16 the spars lalso pass.

ing through the forward and rear portions thereof. V This wing portion 21 isv also stream-lined, its upper and lower 'surfa'ces having'substantiallyfthe same curvature but the 4outer end portions ofthe wings beyond the housing 20, may be given any desired cross-sectional contour to give the desired lifting action in flight.

` Asshown in the'drawlngs (Figs. 3 and 10) the lowerrsurface of yeach of these por-v tions of the wings is formed with la double concave, the concave 22 of the greatest depth being located' approximately at the center of pressure and the concave 23 of lesser dept-hbeing located just forwardly of the trailin edge ofthe plane. This construction o plane provides great lifting power with a minimum of head resistance and -is especially adapted for scout machines where great speed is required.-- 4

To reduce head resistance of the wheels 15- when the machine is in lflight with the chas- `sis in retracted position,^a hood '24 is prov ided for the rear edge of the lower por# tion of each wheel upon, the lower side of wheels when the aeroplane is in flight. Ob-

viously the housing 20 and hood 24 may .he

dispensed with in aeroplanes having very large wings, the wheels in suchmachines beving housed within the wing between the upper'jand lower vwing skins.

The ,chassis is, held in extended position for alighting, by suitable` rack bars 25 piv-A otally attached at `25a to the axle and ex- `tend1ng upwardly and -rearwardly therefrom through lsuitable openings in the skin 26 of "the fuselage, which skin is preferably spaced from the fuselage lframing to proeach win C, and'this hood is stream lined rearward y to provide stream lining yfor/thev vide .a chamber'or space between the frame and skin to receive these racks when they..4

are projected upwardly therein upon retracis constructed as shown-in Figs. 18, 19, 2() I and 121, of a tube 27 preferably of stream lined' contourin cross section with a longi- .tudinal slot in its forward or flat side which'` slotis-'closed by a plate or, strip 28+brazed I or otherwise secured within the tube and provided. with two longitudinal rows' of holes 29 to ,be engaged by sprocket teeth 30 on the hub or projecting end of a transverse shaft 31 mounted in suitable bearing brackets 32 secured to the fuselage framing.-

- The strip 28 forms a longitudinal way within the tube 27 fora plate 32a to which straps 33 embracing the hub of the sprocket tube: 27 ,j thus holding the rack in engage-V l30 are firmly secured in any suitable. man 1 105 tion of the chassis. i Each of the racks 25 j 60 v pilots seat in the machine and are provided .with heads 48 with springs 49 interposed shaft 31 is preferably divided intermediate its ends so that the two parts may be inl serted endwise through the bearings 32 and a coupling 38 connects the inner/ends of the two parts of this shaft rigidly so that they turn as a solid-shaft, the coupling being securelyheld engaged by a locking sleeve 39.

Any suitable motor may be provided for driving the shaft 36 and through the worm gears, rotatingv the shaft 31 to turn the sprockets 3() in engagement with the racks 25 and thus raise or lower the chassis, said chassis being locked in any position'to which it is adjusted by means of the intermeshing of the worms 35 and 37 which at all times prevent longitudinal movementof theracks except when the worms are driven by the i' motor. The chassisl may therefore function as a landing device in anyposition in which it vhappens tobe when its wheels come inr contact with the ground, and it is therefore not necessary that the chassis be fully extended before a landing can be made.

In Figs. 10 and 11 a suitable wind motor is shown for raising or lowering the chassis,

-this motor comprising a small wind wheel 38 mounted upon a suitable bracket 39 projecting laterally from the side of the fusel lage through the skin thereof and firmly secured to the chassis frame. The shaft of the 4- .wheel 38 is provided with a bevel gear 40 v fortherods.

f in mesh with a like" gear on a shaft 41 mounted on .the bracket and extending into the fuselage. Free to rotate upon the shaft, v41 (see Figs. 11 and 16) are bevel gears 42 arranged 'in opposed and spaced relation and in mesh with a similar gear 43 on the upper end of theshaft 36, The gears l42 are formed with clutch faces to be engaged by a clutch member 44 operatively connected to the shaft 4 1 to turn therewith, as by a spline, and free to slide longitudinallythereon into engagement with the clutch face' of either gear.' A -Tshaped operating lever 45 is pivoted upon the bracket 39 with its long arm operatively connected with the clutch member 44 to shift the same upon the turning of the lever by means of rods 46 and 47 conn cted to the short arms ofthe T-leyer.l Thes rodsA extend to a point adjacent the between the heads anda suitable support These springs act equally upon the rods and normally 'hold the lever 45 in of engagement with the clutch faces of the gears 42. The wind wheel is thus normally free to turn without imparting motion to the shaft 36 for raising or lowering the chassis, but when the pilot presses upon one of the heads 48, the clutch 44 will be shifted into engagement witha clutch face of one of the gears 42 thus connecting the shaft 41 with the shaft 36 and motion will be imparted to the shaft 31 and sprockets 30 for turning them in the desired direction to raise or lower the rack bars land retract or .extend the chassis.

Fig. 17 illustrates, diagrammatically, a covering for a pivot joint between an operating planey and lits support, such as between the rudder plane G and the rear end of the fuselage or between the elevating plane I vand fixed stability plane H, the pivot 50 being of any desired construction. In order face which at the same time will yield or bend to permit the free turning of the pivoted plane.

In Figs. 24 and 25 another form of wind operated power device is shown for raising and lowering the retractible chassis. This wind operated device comprises a plane or aerofoil 53 having, preferably, convex upper and lower surfaces of substantially the "same curvature to present the same'resistanlce for like positive and negative angles of incidence, and this aerofoil is pivotally mounted upon theaxle 54 of thechassis frame 55 between the side members 56` of said frame, the axle being housed by said plane.

` Tubular brace members 57 are pivotally attached at their lower ends to the axle and extend upwardly and rearwardly into the f fuselage to hold the chassis in extended position. A suitable latch or dog 58 is'provided for each member 57 to engage openings 59 and 60 therein and securely hold the chassis in its fully extended or fully retracted posi- I f'so tions. IThe dogs are normally held inposition to engage the openings, by means of springs 61, and an arm 62 on one of the dogs is provided with a push rod 63 by means of which the dogs may be turned out of engagement with the members 57 against the action of'thespring 61, sald dogs being connected to turn together, by a transverse rod 64 forming the pivots .for the dogs. y

To impart a varylng lncidence to the plane.

53 as the chassis is lraised thereby and thus present its greatest surface to the windim-- mediately upon the release of the chassis when it is in extended position, ras shown in full lines in Fig. 24:, and to thereafter vary this incidence as the chassislswings upward so that the plane willl lie parallel with the chassis when it approaches .the endv of its upward movement and enters a suitable opening 65 provided therefor in the .lower skin of t-he fuselage, rods 66 .are pivotally attached at their lower ends tola'terally ex* tending arms 67 on the plane and extend upwardly through the hollowside members J 56 of the chassis frame to near the point of pivotal attachment of these members to the fuselage. The upper end of each rod 66 is provided with a stud extending laterally through anopening inthe side of the member 56 and onthis stutd is a roller 67 to engage cam o'rooves- 68 and 69 in a cam plate 70 whichis rigidly secured to the fuselage alon side the frame member 56. A guide' 71 for t e rod is provided 'in the member 56 to prevent lateral movement of the rod at its' upper end and to permit free longitudinal mowement'. Then the chassisds in lowermost position asshow in full lines in Fig. Q4, the roller 67 is in the entl portion of the slot 68 which end portion is eccentric to the pivot of the frame member 56 so that as. the

frame member swings upwardly, lthe roller' is forced to move downwardly and out. wardly in the end portion of the slot 68 and in so doingfmoves the rod 66 endwise and )through its connection with the plane 53 turns said plane on itsaxisto such a position that it' will presentthe maximum of its` surface to the air and will thus exert; the greatest force to swing the chassis upwardly.

"After the planchas been turned to give it itsma-ximum incidence, the roller 67 engages y the 'substantially concentric portion of the slot 68 and thus the plane is held substantially on a radial line extending to the axis of the pivot of the lframe as this frame' swings upwardly, said plane passing through the opening 65 in the bottom of the chassis in a plane silbstalntially parallel to the. bottom of the chassis.

Upon release of the chassis so that it may again move downward to extended positron,

Jthe roller 6'7 is caused to pass into the ca-m groove 69 by'a/ spring gate 72 forming the dividing wall between the two cam slots, this currentswhichgwill foice' the frame to swing rame has downwardly. `When the chassis vreached. the' limit (if its downward movement, the roller 67 lies in the vlower end 58 which hold it at the'extreme end of its up and down movements, thus permitting the force of air currents' duringrthe fli ht of the machine to .act upon the operating plane or aerofoil to raise or lower the chassis according to the incidence given the plane by the automatic means comprising the cam plates 70 and rods 66. y Y 1 The constructlon of the members 57 is i preferably similar to that of uthe rack" bars E25 previously described,each beingprovided with a rack to be enlarged by a sprocket wheel 7% secured upon the end of-a transverse shaft 7 mounted in suitable bearings upon the rotated by the upward movement of the racks, and to assistin thev final upward movement .of the frame which carries the plane into the opening, in the chassis, aily wheel 7 7 is secured upon this shaft. Vhen the chassis is in extended position and the dogs 58 are released, the wind resistance on the chassis will at once swing it rearwardly jand upwardly, setting the flywheel into rapid rotation lso' that the inertia of this wheel will perform the work of`completing the upward movement of the chassis to house the same withinvthe fuselagel Yhen/ the chassis is in housed tposition, the release of the'dog 58 permits gravity to initiate action of the fly wheel and give the areofoil a negative incidence, when wind' resistance on the aerofoilwill swing t-he chassis downwardly and the inertia of the Hy wheel will complete the nal downward movement.

In order that theaeroplane may present as little head resistance as possible when^in flight with the chassis Ain retracted posit-ion, it is desirable that the opening 6 5 in the fuselage be closed after the housing of the plane therein and to so close this opening,

a sliding door 7 8 is providedl which is preferably automatically moved forward beneath the plane when the chassis reaches theupper end of its movement. lThis door 'is also preferably automatically ope-ned upon the beginnlng of the downwardmove ment of thechassis and to accomplish this automatic opening and closing-of the door, the. shaft 7 6 is provided with two drums 79 loose upon the shaft and each connected to the shaft through the medium of a coiled vfuselage frame. .'llhis shaft 7 6 is therefore i i 1 longitudinally thereon.

,action of the-springs 80. The tension of means.

I sion' of the springs' -84 acting to quickly spring 8() secured at one end to the drum of the 'connecting shaft 64. This releases and at its opposite end to a )clutch member the chassis so that the operating ,aerofoil 81 adapted'to be engaged 'by a correspondmay act automatically to raise it', and this ing clutch member operatively connected to aerofoil coming into contactwith and operthe shaft to turn therewith but free to slide ating the latches 85, `automatically closes Cables 82 are atthe door without .any attention on .the'part tached at one end to the rear port-ion of the of the operator. When it is "desired to lower door and passingk under suitable guide the chassis, it is necessary that the door be l pulleys 83, are wound upon the drums 79. first opened and then the chassis released C'oiled springs 84 are attached at their so that it may pass through .the opening.

. forward endt'o the door 78 near its forward To accomplish this, the clutches 81 are first edge and at their rearends to suitable operated to release the tension of the springs brackets on the fuselage frame. These 80, these clutches Ibeing moved by means springs exert a force to normally hold them/of pivoted levers 89 connected by a rod 90, door in open position, and the door is nor- -and the pivot of one of these levers 89 is a mally locked in openy position when the vertical rod 91 having a crank arm 92 on chassis isin extended position, by means of its upper end to whlch al hand operated dogs 85 carried by the fuselage and adapted rod 93 is. pivptally attached at one end and to engage lugs 86 on the door, each latch extends rearwardly to a point adjacent the being provided with a forwardly extending Vpilots station. On the rod 93 is a cam protail portion 87 adapted to be engaged bythe jection 94 which, after alongitudinal moveoperating plane 53 when said plane reaches ment of the rod whichis sufficient to turn V`'the upper end of its movement lnto they fusethe shaft 91 and leversy 89 to release the lage. The engagement of the plane with clutches, will en age the upper end of the the latchpieces 87 thusautomatically operrod 63 and push ownthereon sufficiently to ates the latches to release the door so that turn the shaft 64 and release the dogs 58.'

it may be closed as soonI as the plane is lfully The automatic opening of the door 78 and within its housing in the fuselage. The u release of the chassis is therefore accomwa'rd swinging movement of the chassis plished bv a single movement'of the rod 93.

frame imparts a rotary motion to the shaft The providing of achamber in the fusela e 76 by reason of the engagement of the racks for la portion ofI or the' entire retractab e with the sprockets on said shaft, and therechassis an'd the providing 0f a Suitable C10- fore, the chassis being down and the door sure for this( chamber with automatic means locked open by the latches 85, as shown in for yopening and closing the closure is a Fig. 24, the upward swinging of the chasvery desirable feature in aeroplane consis will turn thev shaft 76 and put the: struction las when the chassis is retracted .springs 8() under tension, the drums 79 bewith the opening in the fuselage closed, its

ing held against turning by the cables 82 bottom skin presents an'unbroken continuand the clutches 81 being engaged to be ro- 'us surf-ace which offers the' minimum of retated by the shaft and wind up the springs sistance to the passage of the aeroplane thereon. The springs being thus wound, through the air. 4

put the cables 82 under heavy tension so` lVhat I dai-mis;-

that immediately upon the release Iof the l. In combination with an aeroplane, relatches 85 by the operating plane, the' door tractable alighting means and-v means opwill be quickly slid forward, the cables 82 erated by air currents while the aeroplane being wound upon the Vdrums by the turning is in flight for these springs 80 is'suificient' to exert a pull 2. In combination with an aeroplane, re-

retracting said `alighting upon the cables after the door, is fully tractable alighting means, a motor, and?.

closed, and they t us hold it in closed posimeans for transmitting motion from said tion notwithstanding the pull of the springs motor to operate said alighting means, said 84 which are put under tension by the closmotior'rtransmittin'g means beingadapted to ing of the 'door. The springs 8,4 being unhold-said alighting means in any posltion to der tension in order to' open the door, it is which it is,adjusted.

only necessary to release the clutches 81,l 3. In combination with an aeroplane, rethns releasing the tension of the springs 8O tractable alighting means, and means includwhich hold the drums) 7 9, and allow the caing a rack`r and pinion and worm gear means bles to unwind freely therefrom, the tenfor raising and lowering Vsaid alighting means and holding the same against moveopen the door. y ment due to alighting stresses.

The retraction of the dogs 58 to permit the by the operation of therod 63 by meansof *for operating said device, including worm a handle 88 thereon, both dogs being opgear means for holdingv the' said; device erated at the `same tune through the medium .against movement due to alighting stressesu 4. In combination with an aeroplanerey- `retraction of the chassis, is accomplished tractable alighting device, automatic means` .lo to operate the same and lform bracing mem` `bers to hold the chassis in` extended position, a transverse shaft, pinions on the shaft 2'5 1 ing and -holding the racks in engagement 5. In combination with an aeroplane, a

'wing having a convex lower surface, are- 1 tractable chassls frame, openings provlded in said` convex wingsurface to house portlons `of-sa1d chassis frame, andmeans for closing said openings lwhen 'said chassis .frame is housed.r

6. In combination with an aeroplane, a

pivotel landing chassis, a pair of rack bars` pivotally attached at one vend to the chassis in engagement with said racks, means for gnidingand holdingthe racks in.'engage ment'with said pinions, a motora nd irre-,

versible gearing for transmitting motion fromV the motor to the shaft;

7. In combination wlth an aeroplane, a.

pivoted landing chassis, al pair ofl rack bars Apivotally attached at one end to the chassis to operate the same and form-bracing mem* bersto hold the chassis inextended position, A'atransverse shaft, pinions on the shaft in .engagement with said racks, means for gui'd withsaid pinions, a motor operated by air currents during flight of the aeroplane',- and means for transmitting .motion from the motor to sai'dshaft,l including reversing and 'connecting and disconnecting means.

.fuselage formed to receive portions of a re 8. In an aeroplane, the combinationof a` fuselage and lwings formed to provide a. housing for a landing chassis, and a landing chassis adapted tobe housed partially' in 'said fuselage and partially in said wings'.

9. Inan aeroplane, the combinationof a tractable chassis, wings, housings on the wings forj portionsof said chassis, and a chassis to be housed in said fuselage and wing housings. v

`10. vIn an aeroplane, the combination of a.

fuselage and'wings,^ a chassis frame con- "thanthe widt wheels .-uponhe' outer ends of said trans verse portion, housings on the wings: for the nected Ito the fuselage at one end and providedwith landing wheels at itsopposite end, 'said frame having lateral-projections u ppeiZr portions 'fof thel wheelsQ-andfmeans for retracting the' chassis. j

12.' In an aeroplane', the' combination' ofua fuselage 'formed to receiyeportions, .oflzalre tractable chassis, wings formed to receive other portions of said chassis, a chassis v frame pivotally attached at its upper end to 'the fuselage to swing towardand from thev same, ground wheels on the chassis framey outside the vertical plane of the fuselage,

housings on the wings for the upper por-l tions of the wheels, downwardly extending portions onthe wings, forming stream line hoods for the rear sides of the lower porv tions of the wheels, and means for swinging the chassis frame on its pivotal-connection with the fuselage'.

13. In an aeroplane, the combination of a fuselage, a ,chassis frame pivotally attached at one end to the fuselage, rack bars pivotally attached to the lower portion of the. l

frame and extending upwardly into 'the fuselage, said fusela being'formed with a space between the skln and framing thereof at each side for said rack bars and withan opening in 'its lower side to receive said frame, and Vmeans within the fuselage for engaging and operating the rack bars to swing the saidchassis frame.

14. In an aeroplane, the combination of a `fuselage, a chassis frame pivotally attached atone end to the fuselage, rack bars pivotally attached to the lower portion of the frame and extending upwardly into the fuselage, said fuselage being formed with a space between the skin and framing thereof atleach side for said rack bars andwith an opening in its lower side to` receive said ,frame, a'f slidable closure for said opening,J

means within the fuselage forengaging and operatingthe rack bars, and means for op,

erating the sliding closure tov close the opening substantially flush'with the outer surface of the fuselage.

15. In anaeroplane, the vcombination of a.

Awing having an opening therein, a landing chassis retractable into: said opening, and

automatically-'operated means for closing said opening flush with the outer surface of thawing when the chassis is housed therein.

16. In an aeroplane, the combination of a wing having anv opening therein, a landing fchassi'swre'tractable into said opening; and *u .means for closing said opening operated by the retraction of said chassis.

' 17. In an aeroplane, the combination of a vwing having an opening therein, a landing f.

.'1 chassis retractable into said opening, a elosure vfor said opening, and means for autof matically'.operating'sai'd closure.

'\' 18. Inanaeropl'ane, the combination of 'fr-fuselage .havingVK an opening therein, a

anding chassis retractable into said open-v ing, a` closure forsald opening, means for automatically operating said closure, releasedbythe retraction of said chassis to ...fclose the opening, and means for automatically opening the closure.'

In an' aeroplane, the combination of a fuselage having an opening therein, alanding chassis retractable into said opening, a

closure for said opening, means for automatically-closing thelclosure, means for automatically openingv the closure, and inanually operated releasing means for said automatic openingmeans.

20. 4In an aeroplane,'the Combination of a fuselage'having an opening'therein, a land-. k

ing chassis retractable into said opening, a closure for said opening, means for automatically opening and closing said closure,

releasing means for the automatic means' operatedby the operation of the chassis, and manually controlled releasing means for said automatic means. v

21. In an aeroplane, the combination of' a wing provided with Wing spars having an opening between said spars, and a retractable chassis having portions adapted to be housed in said opening during flight and tojclose -said opening.

22. In an aeroplane, the combination ofva fuselage having an opening therein, a' landing chassis retractable into said opening, a

- closure for said opening, and means put under tension by the operation of said chassis for automatically operating said closure.

l- 23. In an aeroplane, the combination of a fuselage havingan opening therein, a landing chassisretractable into said opening, a

closure forpsaid opening, automatic means made effective for operating the closure,\by the operation of said chassis, and releasing meaiisf for said automatic closure operating means.

24.5In an aeroplane, the combination of.

a fuselage having an opening therein, a

landing chassis retractable into said opening, means for operating said chassis, a, cloy sure for said opening, and resilient means for operating'said closure, put under tension by said retracting and extending means.

25.' In an aeroplane, the combination of ,a rfuselage havingan opening therein, a landing chassisretractable into said opening, Y

means for operating said chassis, aclosiire for said opening, a spring for opening said closure, and means operated'by said chassis operating means, for closing the closure.

against the action'of said spring.

26. In an aeroplane,- the combination of a fuselage having an opening therein, alanding chassis retractable into said opening, means for operatingsaid chassis, a closure for said opening, aspring for operating said Iclosure in one direction, and meansl operated by the operation of said chassis for operating said closure in the other direction.

27. In an aeroplane, the combination of a fuselagelh'aving an opening therein, a landingl chassis retractable .into said opening,

,A means for operating said chassis, a closure e for said opening, a spring for operatingsaid closurein one direction, a latch for holding the closure open and adapted to be released by a movement of said chassis, and resilient y mea-iis put under tension by a movement of said chassis while the closure is held by said latch.

28. In an aeroplane,'the combination of a fuselage having an opening therein, a landing chassis retractableinto said opening,

means for operating said chassis, a closure for said opening, springs for opening said closure, a rotatable member turned by 'the retraction of the chassis, resilient means put under tension by the rotation of vsaid rotatablemeiniber and operativelyponnected to' said closure to operate the same against the action of said springs, and means for releasing said.. resilient means topermit said springs to operate.v f

' 29;'In an aeroplane, the combination of a fuselage'having an opening therein, a landing chassis retractable into said opening, means for operating said chassis, a clo`I sure for 4said opening, springs for opening said closure, a latch to hold the closure in open position adapted to be released by the operation of the chassis, resilient means operativelyfconnected rto theclosure 'and put under tension by the chassis operating means to close the closure against the action of said springs, and means "for releasing said resilient means.l

.30. In 'an aeroplane, the combination of` a fuselage having an opening therein, al

chassis frame pivotally attached thereto .to

swing into the opening, rack bars pivotally attached to the chassis frame to move into the fuselage, means on the fuselage for engaging the rack bars to hold 'the same in'adjusted position, a closure for the opening,

means for automatically operating the c losure, and means for `successively releasing` the automatic means and bars to `irst open, the' closure and then permit the lowering l 32. Inan'aeroplane, the combination ofi'. a fuselage, 4a chassisA framef pivotally attached .at one end to the fuselage, a transverse shaft on the fuselage pinions on the shaft, rack ibars pivotally attached at one end to the chassis frame and` each formed with a longitudinal guide Way, strap meinbers embracing the shaft adjacent the p inions and slidable within'the guide Way of the rack bars to hold the rack bars in engagement With the pinionsv and `permit alongitudinal movement relative thereto, and

means for'turning the shaft to operate thel chassis when retracted, automatic. means of extending and retracting said chassis, and releasing means to permit said automatic means toy become effective.

35. In an aeroplane, a main wing, a retractable chassis, recesses provided in said wing to house portions of said chassis when retracted and means to hold said chassis in its intermediate position against movement due to alighting stresses.

36. In an aeroplane, a supporting wing havingA slots adapted ,to house chassis frame members, a retractable chassis. frame, and

power means for altering the position of said frame.

37. In an aeroplane, a wing, a retractable chassis, recesses in the Wing into which the chassis members are adapted to =be retracted, and means for closing the recesses substantially Hush with the external surface of the said wing.

38. In an aeroplane, a retractable chassis, power means for retracting said chassis, means for storing energy expended by said lirst means while said chassis is being retracted, and means for applying the said stored energy to the said chassis to move the same.

39,. In an aeroplane, an alighting device adapted to be moved into a housing during flight, means for moving the said alighting device, means adapted to store energy. exerted by said first named means, and means for applying said stored energy to cause a4 movement of said alighting device.

40. In combination with a retractable chassis lfor aircraft, means for housing the chassis when retracted, means for retaining the chassis in positions-intermediate its extremes of movement, power means to operate the said chassis, and a clutch to connect the power means with the retracting means to.

move the said chassis.

41. In combination with an aeroplane wing, a retractable chassis, a housing on the Wing to receive the said chassis, means for holding said chassis in positions intermediate its extremes of movement, power means for operating said chassis, engaging means between said power means and said chassis, and means including a spring for disengaging said engaging means.

- 42. In combination with an aeroplane, re-

tractable alighting means, operating means therefor, and means for transmitting motion from said "operating means to operate said alighting means, said motion transmitting means being adapted to hold said alighting means in any position to which it is adjusted.l f

In testimony whereof I aiix my signature.

JAMES V. MARTIN. 

